The performance of carbon dioxide lasers, for example, can be greatly improved by flowing the gas through the active region in a manner which does not require large blower equipment or methods to stabilize the plasma. Flowing the gas through the active region of a carbon dioxide laser improves the laser's performance in two ways. First, the gas heating problem can be overcome if the gas flow transit time is much shorter than the characteristic times for diffusion of heat through the cavity walls. The excess heat formed from the discharge by the gas is swept away to a more efficient heat exchanger. Second, new gas is continually being passed into the active laser region.
A major problem, however, with flowing the gas through the active region is the problem of producing a high enough flow rate with a small lightweight blower. The critical parameter is the time that a particular volume of gas stays in the active region.
Flowing the gas through the active region has proven to be unacceptable because the gas flow pushes the plasma downstream. Attempts to align the plasma with magnets have also been generally unsuccessful.